PROCESS FOR PRODUCTION OF A BOBBIN TUBE FOR YARN, DEVICE FOR EMBODIMENT OF SUCH PROCESS, BOBBIN TUBE OBTAINED AND MODE OF UTILISATION OF SAID BOBBIN TUBE

Abstract

The invention relates of a cardboard tube (2) which is applied against rotatory die (10) by means of a narrow marginal end area thereof having a an interior hollow roll (7). Said rotatory die (10) is provided with a concave surface (11) that is designed to form an entrant perimetric step (13)The diamter of the that extends inward by constriction of said narrow marginal area (14). The diameter of the riser thereof is equal to the interior diameter of the cardboard tube (2). At the same time against the interior hollow roll (7) is applied a force (F)to flatten the cavity (9) of the interior hollow roll (7) and apply the wall (8) whereof against the interior face of the wall of the cantilevered end of the cardboard tube(2) formed by the action of its rotatory die (10).

Full Text

PROCESS FOR PRODUING A YARN BOBBIN TUBE,
DEVICE FOR CARRYING OUT SAID PROCESS AND
YARN BOBBIN TUBE SO PRODUCED
DESCRIPTION
Field of the invention
This invention relates to a process for production of a yarn bobbin
tube, a device for embodiment of the process, the bobbin tube obtained
and the mode of utilisation of such in transport and storage.
Such yarn bobbin tubes consist of cardboard cylindrical tubes
having characteristics suitable for serving as support for a yarn wound onto
such by means of crossed winding or other method, in order to allow the
storage and transport of the yarn and guarantee its integrity between a
spinning mill and the preparation section of a weaving mill, or between the
former and other finishing, dying, texturing industrial establishments.
In most cases, this type of cardboard cylindrical tube has a beading
formed interiorly at one of its ends, which forms a marked hollow perimetric
roll; in other cases and less frequently the cardboard tubes either lack a
roll, or have a roll at both ends.
The reels of yarn wound on said cardboard tubes, which in the
present specification will be referred to as bobbins, whether the yarn is
natural, artificial or synthetic, are stored and transported either freely piled
or piled in the interior of cardboard boxes, containers or on pallets wound in
plastic shrink film.
In either case, but especially as concerns pallet transport and
storage, layers of yarn reels are formed which are separated by thick
sheets of cardboard, said sheets having apertures for introduction into the
same of the ends of the bobbin lubes which allow ordered positioning of the
reels in lines and rows or staggered.
In these conditions, such as illustrated in figure 16, the reels of yarn
bear directly by means of their bases on the separators constituted by said
thick sheets of cardboard, on account of which the yarn reels of the lower
layer must support the corresponding weight of all the upper reels, whilst
the cardboard bobbin tubes cannot assist in supporting said weight, given
that the bobbin tubes arranged in the same vertical do not enter into
contact with each other, as can be observed in the figure above mentioned.
This system of storage by piling has another serious drawback
which is especially significant as concerns transport of the bobbins by box
or pallet, since the thick cardboard separator sheets represent a high
percentage of the weight and volume of the consignment, giving rise to
increased package and transport costs.
So as to overcome such drawback, the solution adopted is that the
very cardboard tubes for the bobbins of yarn should themselves support the
entire weight of the yarn reels, by means of stable piling with coupling,
insertion or fitting together of the bobbins of one layer with the bobbins of
the other layers arranged in one and the same vertical.
For the purposes of said solution it is necessary to arrange the
bobbin tubes so that they can be coupled together in linear succession by
means of fitting together of a given end of a bobbin tube in the opposite end
of a second analogous bobbin tube, the solution adopted to enable such
has been to constrain one end of the tube so that the unconstrained end of
a second analogous tube can couple with said constrained end by means
of a slight fitting together.
Nevertheless, such an arrangement of the bobbin tubes that allows
piling with fitting together of the same, and which is well known in tubes and
cones produced in plastic or metallic materials or wood, proves to be far
more difficult when one tries to apply it to cardboard tubes, which confirms
the fact that until now such tubes cannot be found commercially, although a
need for such is obvious.
The problem arises when the ratio between the interior diameter of
the rolled end and the external diameter of the tube is too small.
For years this ratio was considered to be obligatorily:
in which e is the thickness of the tube.
When this ratio was not complied with different means were used,
all of which are known and whose purpose was the compression of the
cardboard to below the above-mentioned ratio. By way of generally known
methods the following may be cited: irregular profiles in the base or the
sides of the mould or die; application of temperature in the mould; insertion
of die stamps at the base of the mould; mechanising of steps; male die
working on female die and insertion of die stamps in the centre of the
mould.
The general problem with these methods continues to be the fact
that the ratio can be slightly improved but only in a certain amount, whilst
the highly energetic actions performed on the cardboard have negative
implications for the strength of the cardboard at the part which receives the
treatment. One of the problems associated with these methods takes the
form of a delamination or exfoliation of the layers of the cardboard, which
results in a reduction of the tube's strength. To compensate this problem it
is very often necessary to resort to a higher paper quality since it offers a
better resistance to delamination.
The problematic confronted in relation to the possibility of
manufacturing a tube capable of being fitted together, tends to develop a
work method that overcomes the limitations of the present systems.
The technical challenge is an important one as proved by the
opinions of the technicians who until the present time thought that
manufacture of a tube having these characteristics was impossible, basing
said opinion on the observable fact that forcing a reduction of diameter in a
cardboard tube was practically impossible due to the delamination
problems brought about by conventional methods. To this problem had to
be added the difficulty of achieving rolled ends in paper with ratios of less
than:
which was beyond the reach of the existing methods.
In order to meet the above requirements, the process which is the
subject of the present invention has been developed, by means of which it
is feasible to manufacture yarn bobbin tubes from conventional cardboard
tubes, obtaining a given bobbin tube by means of specific devices created
expressly for the purpose, thus allowing modes of utilisation of the bobbin
tubes obtained according to the invention to be put into practice.
The subject of the invention is a process for the manufacture of a
cardboard bobbin tube which can be arranged in vertical lineal succession
by means of a light fitting together of a given end of one tube in the
opposite end of a second analogous tube, for the purposes of which the
following conventional operative phases are first performed:
a.- start with a cardboard tube, of a length suitable for the size of
bobbin tube to be obtained;
b.- secure said cardboard tube so that it has a cantilevered free
end part; and
c- bead said free end part of the cardboard tube to form an interior
hollow roll with a substantially toric form,
after which, the invention envisages that the cardboard tube, which
is provided at its cantilevered end with an interior hollow roll has, firstly, a
narrow marginal area thereof, situated in the exterior face of the wall of said
cantilevered end opposite said interior hollow roll, applied against a rotatory
die that has a concave operative surface, which is defined by a progressive
former adopting the negative form of the profile of an entrant perimetric
step to be formed in the cardboard tube by constriction of said narrow
marginal area, the diameter of the riser thereof being of equal or lesser
magnitude than that of the interior diameter of said cardboard tube and,
secondly, said cardboard tube has, simultaneously and centrifugally with
respect to the straight section of said cardboard tube, a force of enough
intensity applied interiorly against said interior hollow roll to flatten the
cavity thereof and apply the wall thereof against the interior face of the wall
of the cantilevered end of the cardboard tube which is formed by the action
of said rotatory die.
A feature of the invention consists in that the intensity of the force
applied to the interior roll is suitable in order that the interior face of the wall
thereof be pressed against the interior face of the wall of the end of the
cantilevered cardboard tube which is formed by the action of said rotatory
die.
Another feature of the process according to the invention consists in
that the force applied interiorly and centrifugally, against the interior hollow
roll of the original cardboard tube, is applied point-by-point in a continuous
sequential manner with progressive intensity.
Another feature of the process lies in the fact that the relative
movement between the rotatory die and the cantilevered end of the original
cardboard tube, is determined by the axial advance and retreat of said
rotatory die with respect to the cardboard tube which is maintained
immobile, or vice versa, during the phase in which the entrant perimetric
step is formed and the interior hollow roll is simultaneously flattened.
For implementation of the above process, the device according to
the invention has been developed, which, substantially, consists in a
rotatory shaft which has a cantilevered end to which is solidly mounted a
cup-shaped die, which, in the interior face of its perimetric wall, has a
stepped profile in which diameters increase from the base wall to the die
mouth, the diameter of said mouth being slightly greater than the exterior
diameter of the cardboard tube provided with the interior roll, whilst in the
interior of said cup-shaped die are provided means for exerting pressure so
as to apply, centrifugally and radially, a point-by-point force in a continuous
sequential manner with progressive intensity.
A feature of the device according to the invention consists in that
the interior stepped profile of the rotatory die perimetric wall, corresponds to
the negative of an entrant perimetric step which one wishes to obtain in the
end marginal area of the cardboard tube provided with the interior roll.
According to a preferred embodiment of the device according to the
invention, the means for exerting pressure on the roll of the cardboard tube
are constituted by a roller mounted off-centre in a freely rotating manner in
the base wall of the rotatory cup-shaped die and arranged so that the
distance between its lateral surface and the interior area of lesser diameter
of said rotatory die perimetric wall is of a magnitude no greater than double
the thickness of the cardboard tube provided with the interior roll.
In accordance with another embodiment of the device according to
the invention the means for exerting pressure on the roll of the cardboard
tube are constituted by a roller mounted on the cantilever of a radial arm of
a concentric shaft which is interior to the rotatory shaft of the cup-shaped
die, which rotatory in a manner different to that of the latter.
The invention envisages that the lateral surface of the pressuring
roller of the device has a cone frustum shape whose smaller diameter end
is orientated towards the exterior of the cup-shaped die, said surface being
either smooth or textured (striated, milled, etc.).
The implementation of the process according to the invention by
means of any of the devices described, allows a bobbin tube to be obtained
having an end area of the tube wall which is formed exteriorly with a slight
entrant perimetric step towards the adjacent free edge of said end area and
with an interior roll which, being produced by the beading of said wall, is
applied to the inner face of said end area of the wall, such that the exterior
diameter of the riser part of said slight perimetric entrant step is equal or
less than the interior diameter of the cardboard tube.
Another feature of the bobbin tube according to the invention
consists in that the bobbin tube interior roll has the inner face of the wall
thereof pressed tightly against the interior face of the cardboard tube over
the entire part corresponding to the narrow marginal end area which has
been constrained.
The bobbin tubes obtained according to the invention allow an
advantageous mode of utilisation, according to which the reels of yarn are
situated on a supporting surface, borne by the unconstricted end of the
bobbin tube and distributed in lines and columns, to form a first layer which
is covered with a cardboard positioning sheet provided with apertures in
correspondence with the bobbin tubes which protrude through such, after
which a second layer of yarn reels is positioned the bobbin tubes thereof
coupling with the equivalent tubes of the yarn reels of the lower layer and
so on until the required number of layers is obtained.
The mode of utilisation of the invention contemplates that the yarn
reels of each layer are solidly joined to the bobbin tubes which thus bear
the weight thereof and in turn transmit the entirety of the load to the lower
tubes of a same column in which they are coupled.
In any respect, as is conventional, the bobbin tubes remain free of
the reel of yarn in two end areas of equivalent width, one of such end areas
being that in which the diameter of the tube is constricted.
According to a preferred mode of utilisation of the yarn bobbin
tubes, the cardboard positioning sheets have a thickness less than the
distance existing between the opposite facing bases of two reels in a same
column, in which the bobbin tubes thereof are coupled with respect to each
other, and between the lower base of the lower reel and the column
supporting surface.
Similarly, according to another mode of utilisation of the yarn bobbin
tubes, the cardboard positioning sheets have a thickness equal to or
slightly greater than the distance between the bases of two reels of a
column in which the bobbin tubes thereof are coupled and between the
lower base of the lower reel of the column and the supporting surface of
such.
To facilitate understanding of the preceding ideas, there follows a
description of a preferred embodiment of the invention, with reference to
the accompanying drawings, in which;
Figure 1, represents, diagrammatically and in diametric section, half
of a conventional rotatory die and a portion of a cardboard tube, such being
suitable in order that said rotatory die deform the end edge of the
cardboard tube transforming said edge into a conventional interior roll;
Figure 2, represents, in a manner analogous to the previous figure,
the same components as illustrated in the previous figure once the
conventional interior roll has been formed, said roll having an interior cavity
which is substantially toric;
Figure 3, represents, diagrammatically, the phase of the process
according to the invention in which the cardboard tube resulting from the
processes of the previous figures such as produced by conventional
processes and methods, in which a rotatory die, shown in diametric section,
receives the forward edge of the interiorly beaded end of the conventional
cardboard tube resulting from figure 2;
Figure 4, represents, diagrammatically, the deformation of the
interior roll of the cardboard tube of figure 3, once said tube has penetrated
to the base of the rotatory die and a force is applied centrifugally in a point-
by-point manner in order to flatten in a continuous sequential manner the
interior hollow roll of the cardboard tube, and to modify the surface of a
narrow end area of the cardboard tube forcing it to adopt the form of a
entrant perimetric step, with the result that the internal face of the wall of
the interior roll is applied against the internal face of said narrow area in
which the entrant perimetric step is formed;
Figure 5, represents, diagrammatically, the final phase of forming of
the entrant perimetric step which configures the constriction of the end of
the bobbin tube according to the invention;
Figure 6, represents a possible preferable embodiment of a device
for carrying out the process according to the invention, in which a cup-
shaped rotatory die is shown, viewed from the mouth thereof, having its
interior wail profiled and an off-centre roller in proximity to said wall;
Figure 7, represents a section through line VII-VII of figure 6;
Figure 8, represents a second possible embodiment of the device
for carrying out the process according to the invention, in which a roller is
illustrated, also in proximity to the profiled interior wall, which is mounted on
a radial arm of a shaft which passes centrally through the rotatory cup-
shaped die;
Figure 9, represents a section through line IX-IX of figure 8.;
Figure 10, represents, diagrammatically, the manner in which the
device of figures 6 and 7 acts;
Figure 11, represents a section through line XI-XI of figure 10;
Figure 12, represents a section through line XII-XII of figure 10;
Figure 13, represents a diametric section of the two ends of the
bobbin tube according to the invention;
Figure 14, represents a bobbin tube according to the invention,
which is shown in longitudinal section with respect to a diametric half;
Figure 15, represents, partially sectioned, the lower end of a first
bobbin tube coupled by slight fitting together with the upper end of a
second bobbin tube analogous to the first;
Figure 16, diagrammatically represents the conventional mode of
arranging the reels in columns the yarn being wound around conventional
bobbin tubes, lacking means for coupling by being fitted together, and
which are seated on thick cardboard sheets serving as separator and
positioner; and
Figure 17, diagrammatically represents, analogously to the previous
figure, the case in which the yarn reels in which said yam is wound on
bobbin tubes according to the invention, are situated in three layers and
arranged with two types of positioning sheet.
Figure 1 shows the conventional means for transforming an initial
cardboard tube 1 into a beaded cardboard tube 2, shown in figure 2, which
is suitable for carrying out the process according to the invention.
In said figure 1 the diametric half of a beading die 3 is shown, being
of the conventional rotatory type, also shown is half of a cantilevered end
part 4 of said initial cardboard tube 1, said end part 4, which axially faces a
profiled annular groove 5 of said beading die 3, is moved in the direction of
the arrow A pressing against said profiled annular groove 5, beading the
wall 6 of the initial cardboard tube 1 to form an interior roll 7 whose wall 8
envelops a cavity 9 having a substantially toric configuration, thus obtaining
the above mentioned beaded cardboard tube 2, as can be observed in
figure 2.
A relative movement is established between the beading die 3 and
the initial cardboard tube 1, according to which the beading die 3, which is
rotatory, is maintained axially immobile, whilst said initial cardboard tube 1
is axially mobile in the direction of arrows A and B and immobile in terms of
rotation, however it is feasible that, axially, the beading die 3 be movable
and that the initial cardboard tube be fixed.
Figure 3 shows the phase prior to the commencement of the
process according to the invention, and shows a diametric section of a
rotatory die 10 which has a concave operative surface 11, which is defined
by a progressive former 12 which is profiled to offer the negative of the
profile of a entrant perimetric step 13 to be formed in the beaded cardboard
tube 2, as can be observed in figures 4, 5, 10 and 11, also shown is a
sectioned end part of a beaded cardboard tube 2 inserted into the mouth of
the concave operative surface 11 of said rotatory die 10.
The beaded cardboard tube 2 as shown in figure 3 in this position is
subjected to an axial force in the direction of arrow A, in order to forcibly
introduce a narrow end area 14 of said beaded cardboard tube 2, whilst
simultaneously, as shown in figure 4, a force F is exerted interiorly on the
roll 7 with enough intensity to flatten the cavity 9 of said roll 7 and apply the
wall 8 thereof against the interior face of the wall 6 of the beaded cardboard
tube 2 as to the narrow end area 13 thereof.
This interior force F, directed centrifugally against the roll 7, is of a
point-by-point application, as shown in figure 4, and is developed in a
continual sequential manner with progressive intensity, until having been
applied, at least once, to the entire perimeter of the roll 7, such as shown in
figure 5, thus obtaining the bobbin tube 15, the subject of the present
invention, as a result of successive transformations of the initial cardboard
tube 1 and of the beaded cardboard tube 2 used in the step prior to the
carrying out of the process according to the invention.
One can observe in figure 4 that the force F applied point-by-point
on an interior roll 7 element, produces the flattening of the wall 8 thereof,
reducing or eliminating, as in this case, the cavity 9, said wall 8 thus being
entirely abutted against the stretch of wall 6 corresponding to the entrant
perimetric step 13 which is created by forming the narrow end area 14 of
the beaded cardboard tube 2, whilst the rest of the interior roll 7 is still
undeformed, said deformation taking place when the point of application of
the force F is moved, which will be in a continual sequential manner with
progressive intensity, said intensity being greatest at said point of
application, said point being moved progressively and continuously on said
interior roll until the shape illustrated in figure 5 is obtained, in which the
beaded cardboard tube 2 has been transformed, by constriction of the
narrow end area 14 to become into the entrant perimetric step 13, in the
bobbin tube 15 according to the invention, as shown in figures 10, 11 and
13.
The force F can be applied by any means allowing pressure to be
exerted point-by-point on one or more points of a same element of the
interior roll 7, as is shown in figure 4, as long as it is able to advance on
said interior roll 7 and deform it according to a continual sequence and with
progressive intensity, which is to say, that it acts with lesser intensity before
the point of maximum applied force is reached and reduces said force as
said point is distanced, said points of application being separated by an
infinitesimal magnitude and being represented by the geometric movement
of the element on which the force F acts, the interior roll 7 thus being
deformed, the cavity 9 being reduced or eliminated and the entrant
perimetric step 13 being formed.
Said force F can be exercised by mechanical means, as is shown in
figures 6 to 9 and which will be described below, or by other means such as
high pressure fluid, ultrasound, stamping, etc.
In the present invention mechanical means which have been tested
with success are preferred, but this does not prejudice investigation into the
other means.
Figures 6 and 7, illustrate a cup-shaped rotatory die 16 which is
constituted by a cylindrical body 17 having an operative recess 18 which
determines a thick wall 19 and a base 20, the interior face of said wall 19
being profiled according to a revolution machining 21 shaping the surface
into the negative of the entrant perimetric step 13 to be formed in the
narrow end area 14 of the beaded cardboard tube 2, whilst in the base 20
of the operative recess 18 there is a roller 22, mounted at an off-centre
point thereof, in a freely rotative manner on a shaft 23 and bearing 24 such
that the lesser distance thereof to the wall 19 will be of a magnitude D no
greater than twice the thickness of the wall 6 of the beaded cardboard tube
2.
In the case of figures 6 and 7, the roller 22 in calendering the
assembly formed by the interior roll 7 and by the wall 6 of the beaded
cardboard tube 2 at the narrow end area 14 thereof, exerts on such a force
F, as illustrated in figure 4, a force which decreases with respect to one
side and increases with respect to the other as the roller motion advances
on the internal roll 7, a roller motion which determines that the force is
continual and sequential and in a progressive manner as described above,
such as is shown in figures 10, 11 and 12.
Analogously, the solution adopted in figures 8 and 9 is also suitable.
In these figures the cup-shaped die 25 also has an analogous operative
recess 18 which determines a thick wall 19 and a base 26, the interior face
of said wall 19 being profiled according to the revolution machining 21, as
in the previous case of figures 6 and 7, whilst the base 26 has a bearing 27
in its centre which is traversed in a rotatory manner by a shaft 28,
concentric with the shaft 29 of the cup-shaped die 25, which has a radial
arm 30 mounted on it and, at the cantilevered end of such, a roller 31,
which is also distanced by D from the interior face of the wall 19.
In either case, the rollers 22 and 31 have a slightly cone frustum
shape, whilst the smaller diameter end of such cone frustum is directed
towards the exterior of the operative recess 18, and its lateral surface can
be smooth or textured, in the latter case the finishing adopted can be
striated, grained, stippled, a distinctive pattern, etc.
The bobbin tube 15 which is the subject of the present invention,
such as shown in figures 11 to 15 and 17, is constituted by a cylinder with
wall 6 which has one end constrained in the shape of a entrant perimetric
step 13 formed to the interior and to which is entirely abutted the interior roll
7, said entrant perimetric step having at its riser 32 a diameter d which is
equal to the interior diameter of the other end, thus allowing slight coupling
by fitting together, as shown in figures 11, 12, 15 and 17.
The yarn reels 33, in the conventional manner, leave free a narrow
end area 14, in which is situated said entrant perimetric step 13, and an
equivalent area provided at the other end delimited by a perimetric groove
34.
Ordinarily, the yarn reels 33 wound onto beaded cardboard tubes 2,
are arranged for transport and storage in boxes, pallets, containers, etc. so
that they form layers, as can be observed in figure 16, in which the yarn
reels 33 are piled so that their beaded cardboard tubes 2 are aligned but
not in contact, being intercalated between the yarn reels 33 on two
consecutive layers a thick support sheet 35 made from cardboard and
provided with apertures 36 for housing the ends, without entering into
mutual contact, of the corresponding beaded cardboard tubes.
Should the bobbin tubes 15 according to the invention be used for
winding the yarn, the reels 37 are piled with coupling by means of slight
fitting together of the bobbin tubes 15 whilst light positioner cardboard
sheets 38 or 39 are intercalated, having a thickness E1 less than the
separation between two reels 37 or a thickness E2 equal to said
separation.
Obviously, in the arrangement adopted in figure 16, the weight of
the bobbins 33 rests on the thick supporting cardboard sheets 35, which
are very thick and heavy, and the beaded cardboard tubes 2 are not able to
transmit and support said weight since they remain suspended within the
reels 33 and serve only to position the reels 33 with their free ends being
introduced in the apertures 36 of said thick cardboard support sheets 35.
These thick cardboard support sheets 35 represent a drawback in
package and transport, since they increase the volume and weight of the
packaging.
On the other hand, the bobbin tubes 15 according to the invention
allow a mode of utilisation in storage and transport of yarn reels 37 which
reduces the volume and weight of packaging, since the bobbin tubes 15,
being fitted together vertically, as shown in figure 17, and borne on a
supporting surface 40, support the entire weight of the yarn reels 37, the
thick cardboard support sheets 35 are thus no longer necessary and can be
removed, to be substituted by the light cardboard sheets 38 or 39 which are
also provided with positioning apertures 36.
The basic difference of the invention lies in the combination of a
conventional former tool, the rotatory cup-shaped die 16 and 25, which
incorporates in the interior thereof a rotatory device, the rollers 22 and 31,
which is capable of strongly compressing the cardboard without producing
undesirable delamination.
This technology need not be restricted to obtaining the yarn bobbin
tubes of the invention, but also offers considerable advantages in all
beading, polishing and compacting operations and other similar operations
in the manufacture of cardboard tubes.
I/We claim :
1. Process for producing a yarn bobbin tube, more particularly a
cylindrical cardboard tube which, being one of such as is designed for
storage, transport and handling of yarn wound into reels, allow one tube by
means of a given end thereof to be coupled in linear succession by light fitting
together in the opposite end of another analogous tube comprising :
preparing a cardboard tube, of a length which is suitable for the
size of the bobbin tube to be obtained;
securing said cardboard tube so that it has a cantilevered free end
part, said free end part of the cardboard tube being beaded to form
an interior hollow roll having a substantially toric configuration,
applying the cardboard tube, which is provided at its cantilevered
end with an interior hollow roll and has, firstly, a narrow marginal
area thereof, situated in the exterior face of the wall of said
cantilevered end opposite said interior hollow roll, against a
rotatory die that has a concave operative surface, which is defined
by a progressive former adopting the negative form of the profile of
an entrant penrnetric step;
forming an entrant step in the cardboard tube by constriction of
said narrow marginal area, the diameter of a riser thereof being of
equal or lesser magnitude than that of the interior diameter of said
cardboard tube; and simultaneosly and radially with respect to the
straight section of said cardboard tube, applying a force of enough
intensity interiorly against said interior hollow roll to flatten the
cavity thereof and apply the wall thereof against the interior face of
the wall of the cantilevered end of the cardboard tube which is
formed by the action of said rotatory die.
2. Process for the production of a yarn bobbin tube, as claimed in
claim 1, wherein the force appling step comprises applying force to the
interior roll that is operative to cause abutment of the interior face of the wall
thereof against the interior face of the wall of the cantilevered end of the
cardboard tube which is shaped by the action of said rotatory die.
3. Process for the production of a yarn bobbin tube, as claimed in
claim 1, wherein the force applying step comprises applying the force
interiorly and centrifugally against the hollow interior roll of the cardboard tube
in point-by-point application, and in a continual sequential manner with
progressive intensity.
4. Process for the production of a yarn bobbin tube, as claimed in
claim 1, involving the step of at least one of axially advancing and axially
retreating so that the relative movement between the rotatory die and the
cantilevered end of the cardboard tube is determined by said rotatory die with
respect to the cardboard tube which is maintained immobile, during the phase
in which the entrant perimetric step is formed and the interior hollow roll is
simultaneously flattened.
5. Device for carrying out the process for producing a yard bobbin
tube (15) as claimed in any one of claims 1 to 4, which complements any one
of ihe known devices for beading an end of a cardboard tube (1) by forming
an interior hollow roll (7), wherein said device comprises a rotary shaft having
a cantilevered end on which is solidly mounted a cup-shaped die (16; 25),
the interior face of the perimetric wall (19) thereof having a stepped profile
(21) with diameters increasing from the base wall to the die mouth, the
diameter of which is slightly larger that the exterior diameter of the cardboard
tube (2) provided with the interior roll (7), whilst in the interior of the same
there are means (22; 31) of exerting pressure for applying, radially and
centrifugally, a point-by-point force in a continual sequential manner with
progressive intensity.
6. Device for producing a yard bobbin tune (15) as claimed in claim
5, wherein the interior stepped profiling (21) of the perimetric wall (19) of the
rotaroty die (16; 25) corresponds to the negative of a entrant perimetric step
(13) which one wishes to obtain in the end marginal area (14) of the
cardboard tube (2) provided with the interior roll (7).
7. Device for producing a yarn bobbin tune (15) as claimed in claim
5, wherein the means of exerting pressure on the roll (7) of the cardboard
tube (2) comprise a roller (22) mounting off-centre in a freely rotating manner
in the base wall (20) of the cup-shaped rotatory die (16) and arranged so that
the distance (D) between the lateral surfaces thereof and the interior area of
lesser diameter of the perimetric wall (19) of said rotatory die (16) is of a
magnitude no more than double the thickness of the cardboard tube provided
with the interior roll (7)
8. Device for production of a yam bobbin tune (15) as claimed in
claim 5, wherein the means of exerting pressure on the roll (7) of the
cardboard tube (2) comprise a roller (31) mounted on the cantilever of a radial
arm (30) of an interior concentric shaft (28) of the rotatory shaft (29) of the
cup-shaped die (25). which is rotatory in a manner different to the latter.
9. Device for production of a yarn bobbin tune (15) as claimed in
claims 7 or 8, wherein the roller (22;21) for exerting pressure has a cone
frustum shape the smaller diamter end thereof being orientated towards the
exterior of the cup-shaped die (16;25)
10. Device for production of a yarn bobbin tune (15) as claimed in
claims 7 or 8, wherein the roller (22;21) for exerting pressure has a
substantially textured lateral surface.
11. Yarn bobbin tube (15), more specifically a bobbin tube produced by
the process as claimed in any one of claims 1 to 4 and which is of the type of
cardboard tube which is cylindrical and designed for storage and transport of
yarn from a spinning mill to a weaving mill or other destinations, said bobbin
tubes being able to be fitted together in successive vertical alignment,
wherein it has an end area (14) of the wall (6) of the tube which is shaped
exteriorly with a slight entrant perimetric step (13) towards the free end
adjacent to said end area (14) and has an interior roll (7) which, being formed
by the beading of said wall (6), is applied to the interior face of said end area
(14) of the wall (6). so that the exterior diameter (d) of the riser part (32) of
said slight entrant perimetric step (13) is equal or less than the interior
diameter of the cardboard tube.
12. Yarn bobbin tube (15) as claimed in claim 11, wherein the interior
roll (7) of the bobbin tube has the interior face of the wall (8) thereof tightly
abutted asainst the interior face of the wall (6) of the cardboard tube with
respect to the entire part corresponding to the end marginal area (14) which
has been constricted.

The invention relates of a cardboard tube (2) which is applied against
rotatory die (10) by means of a narrow marginal end area thereof having a an
interior hollow roll (7). Said rotatory die (10) is provided with a concave surface
(11) that is designed to form an entrant perimetric step (13)The diamter of the
that extends inward by constriction of said narrow marginal area (14). The
diameter of the riser thereof is equal to the interior diameter of the cardboard
tube (2). At the same time against the interior hollow roll (7) is applied a force
(F)to flatten the cavity (9) of the interior hollow roll (7) and apply the wall (8)
whereof against the interior face of the wall of the cantilevered end of the
cardboard tube(2) formed by the action of its rotatory die (10).